The polyamines, spermidine (Spd) and spermine (Spm), have been measured in whole blood extracts from control volunteers, patients with cystic fibrosis (CF), and CF obligate heterozygotes. Male homo- and heterozygotes for CF exhibit an elevated Spd/Spm ratio. Female Spd/Spm ratios fluctuate substantially when compared with values obtained for males, and appear to rise and fall as a function of the menstrual cycle. Whole blood fractionated into its various cellular components revealed that greater than 90% of Spd and 70% of Spm were associated with erythrocytes. Comparison with control subjects revealed that Spd/Spm ratios in erythrocytes were significantly higher in CF patients. Spd and Spm were not found in whole body sweat although putrescine was found to be present. Preliminary data suggests that the arginine/putrescine ratio in sweat of individuals may be increased when compared to values obtained from controls. Comparison of electrolyte concentrations and sweat rates via a metabolic chamber to values obtained via pilocarpine iontophoresis were found to be comparable in both normal and pathologic subjects.